No, Unless you change the armature, the shaft is actuly part of the armture unless gear driven. Cheaper solution to replace. When I was a younger Idiot, I did a temperary repair a broken shaft like you mentioned by taking a 2 inch wide shaft collar drilled for set screws on both sides. I was fortunate that I had a long shaft to begin with, which we also determined to be part of the reason the shaft fractured where it did. Again this was just temperary.